Limekiln



(No Model.) 3 Sheets-Sheet 1.

S. W. MoLOON.

' LIMEKILN.

No. 546,935. Patented Sept. 24, 1895.

ANDREW E GRAHAM.PHOTO-UTHO.WA5HINGTON.DC

3 SheetsSheet 3.

s. W. .lvrtLoow.

LIMEKILN.

(No Model.)

Patented Sept. 24, 1895.

e wv e I d If. A

Mrs STATES- SILAS W. MCLOON, OF ROCKLAND, MAINE.

LIMEKILN.

SPECIFICATION forming part of Letters Patent No. 546,935, dated September 24, 1895.

Application filed May 22, 1895- Serial No. 550,251.

To all whom it may concern:

Be it known that I, SILAS W. MoLooN, a citizen of the United States, residing at Rockland, in the county of Knox and State of Maine, have invented. certain newand useful Improvements in Limekilns, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to new and useful improvements in kilns for burning lime-rock, and it has for its object to produce a kiln in which coal may be used for fuel with greatly increased results in the operation of the kiln.

WVith these ends in View the invention consistsin certain novel features of construction of kilns hereinafter described, and particularly set forth in the claims appended. v

In the drawings, Figure 1 is vertical sectional view of the kiln. Fig. 2 is a horizontal section thereof on line 2 2 of Fig. 1. Fig. 3 is a detail vertical sectional view on line 3 3 of Fig. 2. Fig. 4 is a detail sectional view showing the preferred construction of the furnace-arch and its supporting-pillars, and Fig. 5 is a sectional view taken on line 5 5 of Fig. 4.

Referring to the various parts by numerals, 1 designates the flue ofthe kiln in which the lime-rock is burned; 2 2, the furnaces, which are located on diametrically-opposite sides of the flue.

Each furnace consists of a fire-box 3, the top of which is formed by an arch 4, which inclines upwardly from the front wall of the fire-box inwardly, said arch extending to the inner edge of the flue-wall. This arch at its inner end is supported by a pair of pillars 5, which are each formed with straight sides, as shown, to permit of the free passage of the heat from the furnace through the spaces between them into the flue 1. The lower ends of these pillars rest on the bridge-wall 6, which is of the same depth as the pillars and extends from the inner edge of the fire-box to the inner edge of the wall of the flue 1. This bridge-wall inclines upwardly from the fire-box to the flue, as shown, its outeredge that is, the edge coincident with the fire-box wallbeing on a level with the grate 7 in the fire-box. The pillars 5 5 are separated from each otherand from the side walls of the fire- (No model.)

box to form the flues or spaces 9, through which the heat passes into the flue 1. Below the grate 7 of each furnace is the ash-pit 10, which is provided with the usual door 11. Each ash-pit is equal in area to the grate directly above it, and each contains a pan 12, which covers its entire area and rests on the bottom thereof, said pans being about four inches in depth. Entering each ash-pit just above the pan 12 therein is a valved water-supply pipe 13, through which water flows from a suitable source to supply the pans 12, as will be more fully hereinafter described. Entering each ash-pit just above the pan 12 therein is a large pipe 14, which is connected to a blowerl5 or other suitable supply of air under pressure. A valve 16 is placed in each pipe 14, in order that the air-supply may be regulated or entirely cut oil? when desired.

The arches4and pillars5 may be of anysuitable construction and material; but it is preferred to form them as shown in Figs. 4 and 5. In this construction the arch 4 is formed of a strong metal shell, which extends over the entire furnace, its front edge being supported in the furnace-wall and its rear end being supported by the pillars 5. These pillars are also formed of metal shells, which shells open at their lower ends into a hollow bridge-wall 30, which forms their base, and communicate at their upper ends with the hollow arch, as shown in Fig. 5. The side walls 26 of the fire-box are also formed of metal and are hollow, as shown, and form substantially a continuation of the hollow arch and communicate therewith at their upper ends. These hollow sides communicate with the hollow bridge-wall at their lower inner ends. A dome 20 extends upwardly from the outer end of the hollow arch, and from this dome a pipe 21 extends upwardly, its upper end entering the flue at an angle of about forty-five degrees and terminating a sufficient distance above the openings 9 to be above any burned rock in the due. The hollow walls and pillars and the hollow arch are filled with water by means of a pipe 28, which connects with a suitable force-pump or injector. Water-gages 24 are connected to the hollow arches in order to indicate the level of the water over the furnaces, and suitable ICO steam-gages are also connected to the hollow arch, as is manifest. By means of this construction I provide a cheap furnace, which will not burn out as quickly as furnaces formed entirely of fire-brick, and by means of which I am enabled to send jets of steam up into the rock contained in the flue and thereby increase the draft on the furnaces. An automatic safety-valve 25 is placed in pipe 21 and permits the steam to automatically blow off into the flue 1 at a predetermined pressure.

In operation the pans 12 are filled with water by means of the pipes 13. The coal fire is built in the fire-box in the usual way, and air is forced through the pipe 14, this draft being regulated by the valve 16. As the hot ashes and cinders drop through the grates they fall into the water below and produce a vapor or moist steam, which is carried by the air-blast up through the grates and into the bed of coals. This blast of vapor keeps the grates cool and of an even temperature throughout, as it comes in contact with the entire grate, and thereby prevents them from being burned out, and also serves the purpose of increasing the combustion and keeping it more evenly distributed through the furnace. The vapor constantly rising through the grates will keep them cool and free from clinkers. The forced draft used with the rising vapor produces a draft well adapted for burning coal. The vapor is heated as it rises and contacts with the grates and tends to form a vacuum below, into which the cold air and vapor rush. This action creates a strong draft and assists combustion by adding oxygen. The vapor also absorbs sulphurous gases and prevents them from being absorbed by the lime. As the water passes off in vapor from thepans 12 it is supplied through the pipes 13.

By constructing each furnace with the upwardly and inwardly inclined arch 4: and providing the straight pillars 5 5 it will be readily seen that the heat and products of combustion from the furnaces will pass unobstructedly into the flue 1, and in consequence the arch 4 and the tops of the pillars 5 will not be so quickly burned out as they are in the kilns with arches which are level from their outer to their inner ends.

The object of inclining the bridge-wall as described is to aid in directing the heat into the flue and to prevent the ashes and coal in the furnace from working up into the flue. This upward extension of the bridge-wall also aids in holding the lime in the flue. In practice the bridge-wall and the pillars 5 will be of considerable thickness, preferably about twenty-two inches, in order that the distance from the fire box to the flue 1 will be sufficiently long to form draft-fines of the spaces 9 between the pillars and thereby increase the draft on the furnaces. The flue 1 extends below the furnaces, as shown, and is provided with the usual draw-door (not shown) through which the lime is removed.

It will be readily seen that a furnace constructed as described will be Well adapted for burning wood as well as coal for fuel.

Having thus fully described my invention, what I claim is- 1. In a furnace the combination of a draft flue, and a fire box connected therewith, of a hollow arch forming the top of the fire-box, a dome formed on said arch, a pipe leading from said dome into the flue above the fire box connection therewith, an automatic valve in said pipe whereby the steam will pass into the draft flue at a predetermined pressure, and a water supply-pipe connected to the hollow arch, substantially as described.

2. In a kiln for burning lime the combination of a flue, a furnace connected therewith, said furnace being formed with the hollow arch 4, hollow side walls 26, the hollow pillars 5, 5, and hollow bridge-wall connecting and communicating with said pillars, all connected together, a water-supply connected to said hollow walls, a steam pipe connected to the arch and opening into the flue above the furnace connection therewith, substantially as described and for the purpose set forth.

In testimony whereof I ailix my signature in presence of two witnesses.

SILAS \V. MCLOON.

Witnesses:

JOSEPH E. MOORE, EDWARD BROWN. 

